Commit | Line | Data |
---|---|---|
e8af40ee | 1 | ;;; follow.el --- synchronize windows showing the same buffer |
ab422c4d PE |
2 | ;; Copyright (C) 1995-1997, 1999, 2001-2013 Free Software Foundation, |
3 | ;; Inc. | |
e79016aa | 4 | |
c86b6fd2 | 5 | ;; Author: Anders Lindgren <andersl@andersl.com> |
ec8d89ec | 6 | ;; Maintainer: FSF (Anders' email bounces, Sep 2005) |
c86b6fd2 | 7 | ;; Created: 1995-05-25 |
f5f727f8 | 8 | ;; Keywords: display, window, minor-mode, convenience |
e79016aa | 9 | |
dcde1278 RS |
10 | ;; This file is part of GNU Emacs. |
11 | ||
eb3fa2cf | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
e79016aa | 13 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
14 | ;; the Free Software Foundation, either version 3 of the License, or |
15 | ;; (at your option) any later version. | |
e79016aa | 16 | |
dcde1278 | 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
e79016aa KH |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
eb3fa2cf | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
e79016aa KH |
24 | |
25 | ;;; Commentary: | |
26 | ||
ff753438 | 27 | ;; `Follow mode' is a minor mode for Emacs and XEmacs that |
e79016aa KH |
28 | ;; combines windows into one tall virtual window. |
29 | ;; | |
30 | ;; The feeling of a "virtual window" has been accomplished by the use | |
31 | ;; of two major techniques: | |
32 | ;; | |
1ece6cdb | 33 | ;; * The windows always display adjacent sections of the buffer. |
e79016aa | 34 | ;; This means that whenever one window is moved, all the |
17f6d002 | 35 | ;; others will follow. (Hence the name Follow mode.) |
e79016aa | 36 | ;; |
cb02be17 KH |
37 | ;; * Should the point (cursor) end up outside a window, another |
38 | ;; window displaying that point is selected, if possible. This | |
39 | ;; makes it possible to walk between windows using normal cursor | |
e79016aa KH |
40 | ;; movement commands. |
41 | ;; | |
ff753438 | 42 | ;; Follow mode comes to its prime when a large screen and two |
08a1dbe6 | 43 | ;; side-by-side window are used. The user can, with the help of Follow |
1ece6cdb EZ |
44 | ;; mode, use two full-height windows as though they are one. |
45 | ;; Imagine yourself editing a large function, or section of text, | |
c8d05b03 | 46 | ;; and being able to use 144 lines instead of the normal 72... (your |
e79016aa KH |
47 | ;; mileage may vary). |
48 | ||
e79016aa | 49 | ;; To test this package, make sure `follow' is loaded, or will be |
08a1dbe6 | 50 | ;; autoloaded when activated (see below). Then do the following: |
e79016aa | 51 | ;; |
ff753438 | 52 | ;; * Find your favorite file (preferably a long one). |
e79016aa | 53 | ;; |
ff753438 RS |
54 | ;; * Resize Emacs so that it will be wide enough for two full size |
55 | ;; columns. Delete the other windows and split the window with | |
56 | ;; the commands `C-x 1 C-x 3'. | |
e79016aa KH |
57 | ;; |
58 | ;; * Give the command: | |
59 | ;; M-x follow-mode <RETURN> | |
60 | ;; | |
61 | ;; * Now the display should look something like (assuming the text "71" | |
62 | ;; is on line 71): | |
63 | ;; | |
64 | ;; +----------+----------+ | |
65 | ;; |1 |73 | | |
66 | ;; |2 |74 | | |
67 | ;; |3 |75 | | |
cb02be17 | 68 | ;; ... ... |
e79016aa KH |
69 | ;; |71 |143 | |
70 | ;; |72 |144 | | |
71 | ;; +----------+----------+ | |
72 | ;; | |
73 | ;; As you can see, the right-hand window starts at line 73, the line | |
08a1dbe6 | 74 | ;; immediately below the end of the left-hand window. As long as |
1ece6cdb | 75 | ;; `follow-mode' is active, the two windows will follow each other! |
e79016aa KH |
76 | ;; |
77 | ;; * Play around and enjoy! Scroll one window and watch the other. | |
08a1dbe6 SM |
78 | ;; Jump to the beginning or end. Press `Cursor down' at the last |
79 | ;; line of the left-hand window. Enter new lines into the | |
80 | ;; text. Enter long lines spanning several lines, or several | |
e79016aa KH |
81 | ;; windows. |
82 | ;; | |
83 | ;; * Should you find `Follow' mode annoying, just type | |
cb02be17 | 84 | ;; M-x follow-mode <RETURN> |
e79016aa KH |
85 | ;; to turn it off. |
86 | ||
87 | ||
53964682 | 88 | ;; The command `follow-delete-other-windows-and-split' maximizes the |
e79016aa KH |
89 | ;; visible area of the current buffer. |
90 | ;; | |
91 | ;; I recommend adding it, and `follow-mode', to hotkeys in the global | |
92 | ;; key map. To do so, add the following lines (replacing `[f7]' and | |
93 | ;; `[f8]' with your favorite keys) to the init file: | |
94 | ;; | |
e79016aa | 95 | ;; (global-set-key [f8] 'follow-mode) |
e79016aa KH |
96 | ;; (global-set-key [f7] 'follow-delete-other-windows-and-split) |
97 | ||
98 | ||
e4920bc9 | 99 | ;; There exist two system variables that control the appearance of |
1ece6cdb EZ |
100 | ;; lines wider than the window containing them. The default is to |
101 | ;; truncate long lines whenever a window isn't as wide as the frame. | |
e79016aa KH |
102 | ;; |
103 | ;; To make sure lines are never truncated, please place the following | |
104 | ;; lines in your init file: | |
105 | ;; | |
106 | ;; (setq truncate-lines nil) | |
107 | ;; (setq truncate-partial-width-windows nil) | |
108 | ||
109 | ||
da6062e6 | 110 | ;; The correct way to configure Follow mode, or any other mode for |
1ece6cdb EZ |
111 | ;; that matter, is to create one or more functions that do |
112 | ;; whatever you would like to do. These functions are then added to | |
e79016aa KH |
113 | ;; a hook. |
114 | ;; | |
e79016aa KH |
115 | ;; The keymap `follow-key-map' contains key bindings activated by |
116 | ;; `follow-mode'. | |
117 | ;; | |
118 | ;; Example: | |
119 | ;; (add-hook 'follow-mode-hook 'my-follow-mode-hook) | |
120 | ;; | |
121 | ;; (defun my-follow-mode-hook () | |
122 | ;; (define-key follow-mode-map "\C-ca" 'your-favorite-function) | |
123 | ;; (define-key follow-mode-map "\C-cb" 'another-function)) | |
124 | ||
125 | ||
126 | ;; Usage: | |
127 | ;; | |
1ece6cdb EZ |
128 | ;; To activate, issue the command "M-x follow-mode" |
129 | ;; and press Return. To deactivate, do it again. | |
e79016aa | 130 | ;; |
ff753438 RS |
131 | ;; The following is a list of commands useful when follow-mode is active. |
132 | ;; | |
e79016aa | 133 | ;; follow-scroll-up C-c . C-v |
17f6d002 | 134 | ;; Scroll text in a Follow mode window chain up. |
e79016aa KH |
135 | ;; |
136 | ;; follow-scroll-down C-c . v | |
137 | ;; Like `follow-scroll-up', but in the other direction. | |
138 | ;; | |
139 | ;; follow-delete-other-windows-and-split C-c . 1 | |
1ece6cdb | 140 | ;; Maximize the visible area of the current buffer, |
17f6d002 | 141 | ;; and enter Follow mode. This is a very convenient |
fe7a3057 | 142 | ;; way to start Follow mode, hence we recommend that |
1ece6cdb | 143 | ;; this command be added to the global keymap. |
e79016aa KH |
144 | ;; |
145 | ;; follow-recenter C-c . C-l | |
146 | ;; Place the point in the center of the middle window, | |
147 | ;; or a specified number of lines from either top or bottom. | |
148 | ;; | |
149 | ;; follow-switch-to-buffer C-c . b | |
150 | ;; Switch buffer in all windows displaying the current buffer | |
151 | ;; in this frame. | |
152 | ;; | |
153 | ;; follow-switch-to-buffer-all C-c . C-b | |
1ece6cdb | 154 | ;; Switch buffer in all windows in the selected frame. |
e79016aa KH |
155 | ;; |
156 | ;; follow-switch-to-current-buffer-all | |
157 | ;; Show the current buffer in all windows on the current | |
158 | ;; frame and turn on `follow-mode'. | |
159 | ;; | |
160 | ;; follow-first-window C-c . < | |
161 | ;; Select the first window in the frame showing the same buffer. | |
162 | ;; | |
163 | ;; follow-last-window C-c . > | |
164 | ;; Select the last window in the frame showing the same buffer. | |
165 | ;; | |
166 | ;; follow-next-window C-c . n | |
167 | ;; Select the next window in the frame showing the same buffer. | |
168 | ;; | |
169 | ;; follow-previous-window C-c . p | |
170 | ;; Select the previous window showing the same buffer. | |
171 | ||
172 | ||
173 | ;; Well, it seems ok, but what if I really want to look at two different | |
174 | ;; positions in the text? Here are two simple methods to use: | |
175 | ;; | |
176 | ;; 1) Use multiple frames; `follow' mode only affects windows displayed | |
5eba16a3 | 177 | ;; in the same frame. (My apologies to you who can't use frames.) |
e79016aa KH |
178 | ;; |
179 | ;; 2) Bind `follow-mode' to key so you can turn it off whenever | |
08a1dbe6 | 180 | ;; you want to view two locations. Of course, `follow' mode can |
e79016aa KH |
181 | ;; be reactivated by hitting the same key again. |
182 | ;; | |
183 | ;; Example from my ~/.emacs: | |
184 | ;; (global-set-key [f8] 'follow-mode) | |
185 | ||
cb02be17 | 186 | ;; Implementation: |
e79016aa | 187 | ;; |
782fbf2a CY |
188 | ;; The main method by which Follow mode aligns windows is via the |
189 | ;; function `follow-post-command-hook', which is run after each | |
190 | ;; command. This "fixes up" the alignment of other windows which are | |
191 | ;; showing the same Follow mode buffer, on the same frame as the | |
192 | ;; selected window. It does not try to deal with buffers other than | |
193 | ;; the buffer of the selected frame, or windows on other frames. | |
e79016aa | 194 | ;; |
782fbf2a CY |
195 | ;; Comint mode specially calls `follow-comint-scroll-to-bottom' on |
196 | ;; Follow mode buffers. This function scrolls the bottom-most window | |
197 | ;; in a window chain and aligns the other windows accordingly. Follow | |
198 | ;; mode adds a function to `compilation-filter-hook' to align | |
199 | ;; compilation buffers. | |
e79016aa | 200 | |
e79016aa KH |
201 | ;;; Code: |
202 | ||
9271083a JB |
203 | (require 'easymenu) |
204 | ||
c93b886f | 205 | ;;; Variables |
e79016aa | 206 | |
4bef9110 SE |
207 | (defgroup follow nil |
208 | "Synchronize windows showing the same buffer." | |
f5f727f8 DN |
209 | :group 'windows |
210 | :group 'convenience) | |
4bef9110 | 211 | |
4bef9110 | 212 | (defcustom follow-mode-hook nil |
eceb3266 | 213 | "Normal hook run by `follow-mode'." |
4bef9110 SE |
214 | :type 'hook |
215 | :group 'follow) | |
e79016aa | 216 | |
c93b886f | 217 | ;;; Keymap/Menu |
e79016aa | 218 | |
08a1dbe6 | 219 | ;; Define keys for the follow-mode minor mode map and replace some |
782fbf2a CY |
220 | ;; functions in the global map. All Follow mode special functions can |
221 | ;; be found on the `C-c .' prefix key. | |
08a1dbe6 | 222 | ;; |
782fbf2a CY |
223 | ;; To change the prefix, redefine `follow-mode-prefix' before `follow' |
224 | ;; is loaded, or see the section on `follow-mode-hook' above for an | |
225 | ;; example of how to bind the keys the way you like. | |
e79016aa | 226 | |
4bef9110 | 227 | (defcustom follow-mode-prefix "\C-c." |
08a1dbe6 | 228 | "Prefix key to use for follow commands in Follow mode. |
e79016aa | 229 | The value of this variable is checked as part of loading Follow mode. |
4bef9110 SE |
230 | After that, changing the prefix key requires manipulating keymaps." |
231 | :type 'string | |
232 | :group 'follow) | |
233 | ||
08a1dbe6 SM |
234 | (defvar follow-mode-map |
235 | (let ((mainmap (make-sparse-keymap)) | |
236 | (map (make-sparse-keymap))) | |
e79016aa KH |
237 | (define-key map "\C-v" 'follow-scroll-up) |
238 | (define-key map "\M-v" 'follow-scroll-down) | |
239 | (define-key map "v" 'follow-scroll-down) | |
240 | (define-key map "1" 'follow-delete-other-windows-and-split) | |
241 | (define-key map "b" 'follow-switch-to-buffer) | |
242 | (define-key map "\C-b" 'follow-switch-to-buffer-all) | |
243 | (define-key map "\C-l" 'follow-recenter) | |
244 | (define-key map "<" 'follow-first-window) | |
245 | (define-key map ">" 'follow-last-window) | |
246 | (define-key map "n" 'follow-next-window) | |
247 | (define-key map "p" 'follow-previous-window) | |
248 | ||
08a1dbe6 | 249 | (define-key mainmap follow-mode-prefix map) |
e79016aa | 250 | |
17f6d002 | 251 | ;; Replace the standard `end-of-buffer', when in Follow mode. (I |
ff753438 | 252 | ;; don't see the point in trying to replace every function that |
e79016aa KH |
253 | ;; could be enhanced in Follow mode. End-of-buffer is a special |
254 | ;; case since it is very simple to define and it greatly enhances | |
255 | ;; the look and feel of Follow mode.) | |
08a1dbe6 | 256 | (define-key mainmap [remap end-of-buffer] 'follow-end-of-buffer) |
e79016aa | 257 | |
782fbf2a CY |
258 | (define-key mainmap [remap scroll-bar-toolkit-scroll] 'follow-scroll-bar-toolkit-scroll) |
259 | (define-key mainmap [remap scroll-bar-drag] 'follow-scroll-bar-drag) | |
260 | (define-key mainmap [remap scroll-bar-scroll-up] 'follow-scroll-bar-scroll-up) | |
261 | (define-key mainmap [remap scroll-bar-scroll-down] 'follow-scroll-bar-scroll-down) | |
87233a14 | 262 | (define-key mainmap [remap mwheel-scroll] 'follow-mwheel-scroll) |
782fbf2a | 263 | |
08a1dbe6 SM |
264 | mainmap) |
265 | "Minor mode keymap for Follow mode.") | |
e79016aa | 266 | |
7dcef48d SM |
267 | ;; When the mode is not activated, only one item is visible to activate |
268 | ;; the mode. | |
269 | (defun follow-menu-filter (menu) | |
17f6d002 | 270 | (if (bound-and-true-p follow-mode) |
7dcef48d | 271 | menu |
17f6d002 | 272 | '(["Follow mode" follow-mode |
7dcef48d SM |
273 | :style toggle :selected follow-mode]))) |
274 | ||
7dcef48d SM |
275 | (easy-menu-add-item nil '("Tools") |
276 | '("Follow" | |
7dcef48d SM |
277 | :filter follow-menu-filter |
278 | ["Scroll Up" follow-scroll-up follow-mode] | |
279 | ["Scroll Down" follow-scroll-down follow-mode] | |
280 | "--" | |
281 | ["Delete Other Windows and Split" follow-delete-other-windows-and-split follow-mode] | |
282 | "--" | |
283 | ["Switch To Buffer" follow-switch-to-buffer follow-mode] | |
284 | ["Switch To Buffer (all windows)" follow-switch-to-buffer-all follow-mode] | |
285 | "--" | |
286 | ["First Window" follow-first-window follow-mode] | |
287 | ["Last Window" follow-last-window follow-mode] | |
288 | ["Next Window" follow-next-window follow-mode] | |
289 | ["Previous Window" follow-previous-window follow-mode] | |
290 | "--" | |
291 | ["Recenter" follow-recenter follow-mode] | |
292 | "--" | |
293 | ["Follow mode" follow-mode :style toggle :selected follow-mode])) | |
294 | ||
08a1dbe6 SM |
295 | (defcustom follow-mode-line-text " Follow" |
296 | "Text shown in the mode line when Follow mode is active. | |
297 | Defaults to \" Follow\". Examples of other values | |
298 | are \" Fw\", or simply \"\"." | |
299 | :type 'string | |
300 | :group 'follow) | |
301 | ||
302 | (defcustom follow-auto nil | |
303 | "Non-nil activates Follow mode whenever a file is loaded." | |
304 | :type 'boolean | |
782fbf2a CY |
305 | :group 'follow |
306 | :set (lambda (symbol value) | |
307 | (if value | |
308 | (add-hook 'find-file-hook 'follow-find-file-hook t) | |
309 | (remove-hook 'find-file-hook 'follow-find-file-hook)) | |
310 | (set-default symbol value))) | |
08a1dbe6 SM |
311 | |
312 | (defvar follow-cache-command-list | |
313 | '(next-line previous-line forward-char backward-char) | |
314 | "List of commands that don't require recalculation. | |
315 | ||
316 | In order to be able to use the cache, a command should not change the | |
317 | contents of the buffer, nor should it change selected window or current | |
318 | buffer. | |
319 | ||
320 | The commands in this list are checked at load time. | |
321 | ||
322 | To mark other commands as suitable for caching, set the symbol | |
323 | property `follow-mode-use-cache' to non-nil.") | |
324 | ||
78f3273a CY |
325 | (defcustom follow-debug nil |
326 | "If non-nil, emit Follow mode debugging messages." | |
327 | :type 'boolean | |
328 | :group 'follow) | |
08a1dbe6 SM |
329 | |
330 | ;; Internal variables: | |
331 | ||
332 | (defvar follow-internal-force-redisplay nil | |
333 | "True when Follow mode should redisplay the windows.") | |
334 | ||
08a1dbe6 SM |
335 | (defvar follow-active-menu nil |
336 | "The menu visible when Follow mode is active.") | |
337 | ||
72b255c7 PE |
338 | (defvar follow-inactive-menu nil |
339 | "The menu visible when Follow mode is inactive.") | |
08a1dbe6 SM |
340 | |
341 | (defvar follow-inside-post-command-hook nil | |
342 | "Non-nil when inside Follow modes `post-command-hook'. | |
343 | Used by `follow-window-size-change'.") | |
344 | ||
345 | (defvar follow-windows-start-end-cache nil | |
346 | "Cache used by `follow-window-start-end'.") | |
347 | ||
c93b886f | 348 | ;;; Debug messages |
08a1dbe6 SM |
349 | |
350 | ;; This inline function must be as small as possible! | |
351 | ;; Maybe we should define a macro that expands to nil if | |
352 | ;; the variable is not set. | |
353 | ||
354 | (defsubst follow-debug-message (&rest args) | |
5eba16a3 | 355 | "Like `message', but only active when `follow-debug' is non-nil." |
08a1dbe6 SM |
356 | (if (and (boundp 'follow-debug) follow-debug) |
357 | (apply 'message args))) | |
e79016aa | 358 | |
c93b886f | 359 | ;;; Cache |
f3bfa025 | 360 | |
08a1dbe6 SM |
361 | (dolist (cmd follow-cache-command-list) |
362 | (put cmd 'follow-mode-use-cache t)) | |
f3bfa025 | 363 | |
c93b886f | 364 | ;;; The mode |
e79016aa KH |
365 | |
366 | ;;;###autoload | |
367 | (defun turn-on-follow-mode () | |
08a1dbe6 | 368 | "Turn on Follow mode. Please see the function `follow-mode'." |
e79016aa KH |
369 | (follow-mode 1)) |
370 | ||
371 | ||
372 | ;;;###autoload | |
373 | (defun turn-off-follow-mode () | |
08a1dbe6 | 374 | "Turn off Follow mode. Please see the function `follow-mode'." |
e79016aa KH |
375 | (follow-mode -1)) |
376 | ||
08a1dbe6 | 377 | (put 'follow-mode 'permanent-local t) |
e79016aa | 378 | ;;;###autoload |
08a1dbe6 | 379 | (define-minor-mode follow-mode |
06e21633 CY |
380 | "Toggle Follow mode. |
381 | With a prefix argument ARG, enable Follow mode if ARG is | |
382 | positive, and disable it otherwise. If called from Lisp, enable | |
383 | the mode if ARG is omitted or nil. | |
e79016aa | 384 | |
06e21633 CY |
385 | Follow mode is a minor mode that combines windows into one tall |
386 | virtual window. This is accomplished by two main techniques: | |
e79016aa | 387 | |
cb02be17 | 388 | * The windows always displays adjacent sections of the buffer. |
e79016aa | 389 | This means that whenever one window is moved, all the |
17f6d002 | 390 | others will follow. (Hence the name Follow mode.) |
e79016aa | 391 | |
cb02be17 KH |
392 | * Should the point (cursor) end up outside a window, another |
393 | window displaying that point is selected, if possible. This | |
394 | makes it possible to walk between windows using normal cursor | |
e79016aa KH |
395 | movement commands. |
396 | ||
397 | Follow mode comes to its prime when used on a large screen and two | |
3eaf40f7 | 398 | side-by-side windows are used. The user can, with the help of Follow |
e79016aa | 399 | mode, use two full-height windows as though they would have been |
8cd3480b | 400 | one. Imagine yourself editing a large function, or section of text, |
c8d05b03 | 401 | and being able to use 144 lines instead of the normal 72... (your |
e79016aa KH |
402 | mileage may vary). |
403 | ||
404 | To split one large window into two side-by-side windows, the commands | |
2d197ffb | 405 | `\\[split-window-right]' or \ |
e79016aa KH |
406 | `M-x follow-delete-other-windows-and-split' can be used. |
407 | ||
8cd3480b | 408 | Only windows displayed in the same frame follow each other. |
e79016aa | 409 | |
eceb3266 | 410 | This command runs the normal hook `follow-mode-hook'. |
e79016aa KH |
411 | |
412 | Keys specific to Follow mode: | |
413 | \\{follow-mode-map}" | |
08a1dbe6 | 414 | :keymap follow-mode-map |
782fbf2a CY |
415 | (if follow-mode |
416 | (progn | |
417 | (add-hook 'compilation-filter-hook 'follow-align-compilation-windows t t) | |
418 | (add-hook 'post-command-hook 'follow-post-command-hook t) | |
419 | (add-hook 'window-size-change-functions 'follow-window-size-change t)) | |
420 | ;; Remove globally-installed hook functions only if there is no | |
421 | ;; other Follow mode buffer. | |
422 | (let ((buffers (buffer-list)) | |
423 | following) | |
424 | (while (and (not following) buffers) | |
425 | (setq following (buffer-local-value 'follow-mode (car buffers)) | |
426 | buffers (cdr buffers))) | |
427 | (unless following | |
428 | (remove-hook 'post-command-hook 'follow-post-command-hook) | |
429 | (remove-hook 'window-size-change-functions 'follow-window-size-change))) | |
430 | (remove-hook 'compilation-filter-hook 'follow-align-compilation-windows t))) | |
e79016aa KH |
431 | |
432 | (defun follow-find-file-hook () | |
17f6d002 | 433 | "Find-file hook for Follow mode. See the variable `follow-auto'." |
782fbf2a | 434 | (if follow-auto (follow-mode 1))) |
e79016aa | 435 | |
c93b886f | 436 | ;;; User functions |
e79016aa | 437 | |
c93b886f | 438 | ;;; Scroll |
e79016aa | 439 | |
17f6d002 | 440 | ;; `scroll-up' and `-down', but for windows in Follow mode. |
e79016aa | 441 | ;; |
4c36be58 | 442 | ;; Almost like the real thing, except when the cursor ends up outside |
e79016aa | 443 | ;; the top or bottom... In our case however, we end up outside the |
40ba43b4 | 444 | ;; window and hence we are recentered. Should we let `recenter' handle |
e79016aa KH |
445 | ;; the point position we would never leave the selected window. To do |
446 | ;; it ourselves we would need to do our own redisplay, which is easier | |
447 | ;; said than done. (Why didn't I do a real display abstraction from | |
448 | ;; the beginning?) | |
449 | ;; | |
450 | ;; We must sometimes set `follow-internal-force-redisplay', otherwise | |
451 | ;; our post-command-hook will move our windows back into the old | |
452 | ;; position... (This would also be corrected if we would have had a | |
453 | ;; good redisplay abstraction.) | |
454 | ||
455 | (defun follow-scroll-up (&optional arg) | |
17f6d002 | 456 | "Scroll text in a Follow mode window chain up. |
e79016aa KH |
457 | |
458 | If called with no ARG, the `next-screen-context-lines' last lines of | |
459 | the bottom window in the chain will be visible in the top window. | |
460 | ||
461 | If called with an argument, scroll ARG lines up. | |
462 | Negative ARG means scroll downward. | |
463 | ||
17f6d002 | 464 | Works like `scroll-up' when not in Follow mode." |
e79016aa | 465 | (interactive "P") |
782fbf2a | 466 | (cond ((not follow-mode) |
e79016aa KH |
467 | (scroll-up arg)) |
468 | (arg | |
469 | (save-excursion (scroll-up arg)) | |
470 | (setq follow-internal-force-redisplay t)) | |
471 | (t | |
472 | (let* ((windows (follow-all-followers)) | |
473 | (end (window-end (car (reverse windows))))) | |
474 | (if (eq end (point-max)) | |
475 | (signal 'end-of-buffer nil) | |
476 | (select-window (car windows)) | |
ff753438 RS |
477 | ;; `window-end' might return nil. |
478 | (if end | |
479 | (goto-char end)) | |
e79016aa KH |
480 | (vertical-motion (- next-screen-context-lines)) |
481 | (set-window-start (car windows) (point))))))) | |
482 | ||
483 | ||
484 | (defun follow-scroll-down (&optional arg) | |
17f6d002 | 485 | "Scroll text in a Follow mode window chain down. |
e79016aa KH |
486 | |
487 | If called with no ARG, the `next-screen-context-lines' top lines of | |
488 | the top window in the chain will be visible in the bottom window. | |
489 | ||
490 | If called with an argument, scroll ARG lines down. | |
491 | Negative ARG means scroll upward. | |
492 | ||
17f6d002 | 493 | Works like `scroll-up' when not in Follow mode." |
e79016aa | 494 | (interactive "P") |
782fbf2a | 495 | (cond ((not follow-mode) |
e79016aa KH |
496 | (scroll-up arg)) |
497 | (arg | |
498 | (save-excursion (scroll-down arg))) | |
499 | (t | |
500 | (let* ((windows (follow-all-followers)) | |
501 | (win (car (reverse windows))) | |
502 | (start (window-start (car windows)))) | |
503 | (if (eq start (point-min)) | |
504 | (signal 'beginning-of-buffer nil) | |
505 | (select-window win) | |
506 | (goto-char start) | |
cb02be17 | 507 | (vertical-motion (- (- (window-height win) |
99dfcc0d | 508 | (if header-line-format 2 1) |
e79016aa KH |
509 | next-screen-context-lines))) |
510 | (set-window-start win (point)) | |
511 | (goto-char start) | |
512 | (vertical-motion (- next-screen-context-lines 1)) | |
513 | (setq follow-internal-force-redisplay t)))))) | |
514 | ||
782fbf2a CY |
515 | (declare-function comint-adjust-point "comint" (window)) |
516 | (defvar comint-scroll-show-maximum-output) | |
517 | ||
45fdb482 | 518 | (defun follow-comint-scroll-to-bottom (&optional _window) |
782fbf2a CY |
519 | "Scroll the bottom-most window in the current Follow chain. |
520 | This is to be called by `comint-postoutput-scroll-to-bottom'." | |
521 | (let* ((buffer (current-buffer)) | |
522 | (selected (selected-window)) | |
523 | (is-selected (eq (window-buffer) buffer)) | |
524 | some-window) | |
525 | (when (or is-selected | |
526 | (setq some-window (get-buffer-window))) | |
527 | (let* ((pos (progn (comint-adjust-point nil) (point))) | |
528 | (win (if is-selected | |
529 | selected | |
530 | (car (last (follow-all-followers some-window)))))) | |
531 | (select-window win) | |
532 | (goto-char pos) | |
533 | (setq follow-windows-start-end-cache nil) | |
534 | (follow-adjust-window win pos) | |
535 | (unless is-selected | |
536 | (select-window selected) | |
537 | (set-buffer buffer)))))) | |
538 | ||
539 | (defun follow-align-compilation-windows () | |
540 | "Align the windows of the current Follow mode buffer. | |
541 | This is to be called from `compilation-filter-hook'." | |
542 | (let ((buffer (current-buffer)) | |
543 | (win (get-buffer-window)) | |
544 | (selected (selected-window))) | |
545 | (when (and follow-mode (waiting-for-user-input-p) win) | |
546 | (let ((windows (follow-all-followers win))) | |
547 | (unless (eq (window-buffer selected) buffer) | |
548 | (setq win (car windows)) | |
549 | (select-window win)) | |
550 | (follow-redisplay windows win t) | |
551 | (setq follow-windows-start-end-cache nil) | |
552 | (unless (eq selected win) | |
553 | (select-window selected) | |
554 | (set-buffer buffer)))))) | |
555 | ||
c93b886f | 556 | ;;; Buffer |
e79016aa KH |
557 | |
558 | ;;;###autoload | |
559 | (defun follow-delete-other-windows-and-split (&optional arg) | |
17f6d002 | 560 | "Create two side by side windows and enter Follow mode. |
e79016aa KH |
561 | |
562 | Execute this command to display as much as possible of the text | |
cb02be17 | 563 | in the selected window. All other windows, in the current |
e79016aa | 564 | frame, are deleted and the selected window is split in two |
17f6d002 | 565 | side-by-side windows. Follow mode is activated, hence the |
e79016aa KH |
566 | two windows always will display two successive pages. |
567 | \(If one window is moved, the other one will follow.) | |
568 | ||
8cd3480b | 569 | If ARG is positive, the leftmost window is selected. If negative, |
e79016aa | 570 | the rightmost is selected. If ARG is nil, the leftmost window is |
782fbf2a | 571 | selected if the original window is the first one in the frame." |
e79016aa | 572 | (interactive "P") |
cb02be17 | 573 | (let ((other (or (and (null arg) |
e79016aa | 574 | (not (eq (selected-window) |
12b4c0ea | 575 | (frame-first-window)))) |
e79016aa KH |
576 | (and arg |
577 | (< (prefix-numeric-value arg) 0)))) | |
578 | (start (window-start))) | |
579 | (delete-other-windows) | |
2d197ffb | 580 | (split-window-right) |
cb02be17 | 581 | (if other |
e79016aa KH |
582 | (progn |
583 | (other-window 1) | |
584 | (set-window-start (selected-window) start) | |
585 | (setq follow-internal-force-redisplay t))) | |
586 | (follow-mode 1))) | |
587 | ||
588 | (defun follow-switch-to-buffer (buffer) | |
17f6d002 | 589 | "Show BUFFER in all windows in the current Follow mode window chain." |
e79016aa KH |
590 | (interactive "BSwitch to Buffer: ") |
591 | (let ((orig-window (selected-window)) | |
592 | (windows (follow-all-followers))) | |
593 | (while windows | |
594 | (select-window (car windows)) | |
595 | (switch-to-buffer buffer) | |
596 | (setq windows (cdr windows))) | |
597 | (select-window orig-window))) | |
598 | ||
599 | ||
600 | (defun follow-switch-to-buffer-all (&optional buffer) | |
601 | "Show BUFFER in all windows on this frame. | |
602 | Defaults to current buffer." | |
cb02be17 | 603 | (interactive (list (read-buffer "Switch to Buffer: " |
e79016aa KH |
604 | (current-buffer)))) |
605 | (or buffer (setq buffer (current-buffer))) | |
606 | (let ((orig-window (selected-window))) | |
782fbf2a CY |
607 | (walk-windows (lambda (win) |
608 | (select-window win) | |
609 | (switch-to-buffer buffer)) | |
610 | 'no-minibuf) | |
e79016aa KH |
611 | (select-window orig-window) |
612 | (follow-redisplay))) | |
613 | ||
614 | ||
615 | (defun follow-switch-to-current-buffer-all () | |
782fbf2a | 616 | "Show current buffer in all windows on this frame, and enter Follow mode." |
e79016aa | 617 | (interactive) |
782fbf2a CY |
618 | (unless follow-mode |
619 | (follow-mode 1)) | |
e79016aa KH |
620 | (follow-switch-to-buffer-all)) |
621 | ||
c93b886f | 622 | ;;; Movement |
e79016aa | 623 | |
fc779383 | 624 | ;; Note, these functions are not very useful, at least not unless you |
e79016aa KH |
625 | ;; rebind the rather cumbersome key sequence `C-c . p'. |
626 | ||
627 | (defun follow-next-window () | |
628 | "Select the next window showing the same buffer." | |
629 | (interactive) | |
630 | (let ((succ (cdr (follow-split-followers (follow-all-followers))))) | |
631 | (if succ | |
632 | (select-window (car succ)) | |
633 | (error "%s" "No more windows")))) | |
634 | ||
635 | ||
636 | (defun follow-previous-window () | |
637 | "Select the previous window showing the same buffer." | |
638 | (interactive) | |
639 | (let ((pred (car (follow-split-followers (follow-all-followers))))) | |
640 | (if pred | |
641 | (select-window (car pred)) | |
642 | (error "%s" "No more windows")))) | |
643 | ||
644 | ||
645 | (defun follow-first-window () | |
646 | "Select the first window in the frame showing the same buffer." | |
647 | (interactive) | |
648 | (select-window (car (follow-all-followers)))) | |
649 | ||
650 | ||
651 | (defun follow-last-window () | |
652 | "Select the last window in the frame showing the same buffer." | |
653 | (interactive) | |
654 | (select-window (car (reverse (follow-all-followers))))) | |
655 | ||
c93b886f | 656 | ;;; Redraw |
e79016aa KH |
657 | |
658 | (defun follow-recenter (&optional arg) | |
cb02be17 KH |
659 | "Recenter the middle window around point. |
660 | Rearrange all other windows around the middle window. | |
e79016aa KH |
661 | |
662 | With a positive argument, place the current line ARG lines | |
8cd3480b JB |
663 | from the top. With a negative argument, place it -ARG lines |
664 | from the bottom." | |
e79016aa KH |
665 | (interactive "P") |
666 | (if arg | |
667 | (let ((p (point)) | |
668 | (arg (prefix-numeric-value arg))) | |
669 | (if (>= arg 0) | |
670 | ;; Recenter relative to the top. | |
671 | (progn | |
672 | (follow-first-window) | |
673 | (goto-char p) | |
674 | (recenter arg)) | |
675 | ;; Recenter relative to the bottom. | |
676 | (follow-last-window) | |
677 | (goto-char p) | |
678 | (recenter arg) | |
679 | ;; Otherwise, our post-command-hook will move the window | |
680 | ;; right back. | |
681 | (setq follow-internal-force-redisplay t))) | |
682 | ;; Recenter in the middle. | |
683 | (let* ((dest (point)) | |
684 | (windows (follow-all-followers)) | |
685 | (win (nth (/ (- (length windows) 1) 2) windows))) | |
686 | (select-window win) | |
687 | (goto-char dest) | |
782fbf2a | 688 | (recenter)))) |
e79016aa KH |
689 | |
690 | ||
691 | (defun follow-redraw () | |
692 | "Arrange windows displaying the same buffer in successor order. | |
693 | This function can be called even if the buffer is not in Follow mode. | |
694 | ||
695 | Hopefully, there should be no reason to call this function when in | |
696 | Follow mode since the windows should always be aligned." | |
697 | (interactive) | |
698 | (sit-for 0) | |
699 | (follow-redisplay)) | |
700 | ||
c93b886f | 701 | ;;; End of buffer |
e79016aa KH |
702 | |
703 | (defun follow-end-of-buffer (&optional arg) | |
17f6d002 | 704 | "Move point to the end of the buffer, Follow mode style. |
e79016aa KH |
705 | |
706 | If the end is not visible, it will be displayed in the last possible | |
17f6d002 | 707 | window in the Follow mode window chain. |
e79016aa | 708 | |
cb02be17 | 709 | The mark is left at the previous position. With arg N, put point N/10 |
e79016aa KH |
710 | of the way from the true end." |
711 | (interactive "P") | |
712 | (let ((followers (follow-all-followers)) | |
713 | (pos (point))) | |
714 | (cond (arg | |
715 | (select-window (car (reverse followers)))) | |
cb02be17 | 716 | ((follow-select-if-end-visible |
e79016aa KH |
717 | (follow-windows-start-end followers))) |
718 | (t | |
719 | (select-window (car (reverse followers))))) | |
720 | (goto-char pos) | |
2a4b9211 RS |
721 | (with-no-warnings |
722 | (end-of-buffer arg)))) | |
e79016aa | 723 | |
c93b886f | 724 | ;;; Display |
e79016aa | 725 | |
782fbf2a CY |
726 | (defun follow--window-sorter (w1 w2) |
727 | "Sorting function for W1 and W2 based on their positions. | |
728 | Return non-nil if W1 is above W2; if their top-lines | |
729 | are at the same position, return non-nil if W1 is to the | |
730 | left of W2." | |
731 | (let* ((edge-1 (window-pixel-edges w1)) | |
732 | (edge-2 (window-pixel-edges w2)) | |
733 | (y1 (nth 1 edge-1)) | |
734 | (y2 (nth 1 edge-2))) | |
735 | (if (= y1 y2) | |
736 | (< (car edge-1) (car edge-2)) | |
737 | (< y1 y2)))) | |
738 | ||
739 | (defun follow-all-followers (&optional win) | |
740 | "Return all windows displaying the same buffer as the WIN. | |
741 | The list is sorted with topmost and leftmost windows first, and | |
742 | contains only windows in the same frame as WIN. If WIN is nil, | |
743 | it defaults to the selected window." | |
744 | (unless (window-live-p win) | |
745 | (setq win (selected-window))) | |
746 | (let ((buffer (window-buffer win)) | |
747 | windows) | |
748 | (dolist (w (window-list (window-frame win) 'no-minibuf win)) | |
749 | (if (eq (window-buffer w) buffer) | |
750 | (push w windows))) | |
751 | (sort windows 'follow--window-sorter))) | |
e79016aa KH |
752 | |
753 | (defun follow-split-followers (windows &optional win) | |
782fbf2a | 754 | "Split WINDOWS into two sets: predecessors and successors. |
cb02be17 | 755 | Return `(PRED . SUCC)' where `PRED' and `SUCC' are ordered starting |
e79016aa | 756 | from the selected window." |
cb02be17 | 757 | (or win |
e79016aa KH |
758 | (setq win (selected-window))) |
759 | (let ((pred '())) | |
760 | (while (not (eq (car windows) win)) | |
761 | (setq pred (cons (car windows) pred)) | |
762 | (setq windows (cdr windows))) | |
763 | (cons pred (cdr windows)))) | |
764 | ||
e79016aa | 765 | (defun follow-calc-win-end (&optional win) |
c93b886f CY |
766 | "Calculate the end position for window WIN. |
767 | Return (END-POS END-OF-BUFFER). | |
768 | ||
769 | Actually, the position returned is the start of the line after | |
770 | the last fully-visible line in WIN. If WIN is nil, the selected | |
771 | window is used." | |
772 | (let* ((win (or win (selected-window))) | |
773 | (edges (window-inside-pixel-edges win)) | |
774 | (ht (- (nth 3 edges) (nth 1 edges))) | |
775 | (last-line-pos (posn-point (posn-at-x-y 0 (1- ht) win)))) | |
776 | (if (pos-visible-in-window-p last-line-pos win) | |
777 | (let ((end (window-end win t))) | |
778 | (list end (= end (point-max)))) | |
779 | (list last-line-pos nil)))) | |
e79016aa | 780 | |
e79016aa | 781 | (defun follow-calc-win-start (windows pos win) |
782fbf2a CY |
782 | "Determine the start of window WIN in a Follow mode window chain. |
783 | WINDOWS is a list of chained windows, and POS is the starting | |
784 | position for the first window in the list. If WIN is nil, return | |
785 | the point below all windows." | |
786 | (while (and windows (not (eq (car windows) win))) | |
787 | (let ((old-start (window-start (car windows)))) | |
788 | ;; Can't use `save-window-excursion' since it triggers a redraw. | |
e79016aa | 789 | (set-window-start (car windows) pos 'noforce) |
4484b97d | 790 | (setq pos (car (follow-calc-win-end (car windows)))) |
782fbf2a CY |
791 | (set-window-start (car windows) old-start 'noforce) |
792 | (setq windows (cdr windows)))) | |
793 | pos) | |
e79016aa | 794 | |
f3bfa025 KH |
795 | ;; The result from `follow-windows-start-end' is cached when using |
796 | ;; a handful simple commands, like cursor movement commands. | |
797 | ||
798 | (defsubst follow-cache-valid-p (windows) | |
799 | "Test if the cached value of `follow-windows-start-end' can be used. | |
800 | Note that this handles the case when the cache has been set to nil." | |
801 | (let ((res t) | |
802 | (cache follow-windows-start-end-cache)) | |
803 | (while (and res windows cache) | |
804 | (setq res (and (eq (car windows) | |
805 | (car (car cache))) | |
806 | (eq (window-start (car windows)) | |
807 | (car (cdr (car cache)))))) | |
808 | (setq windows (cdr windows)) | |
809 | (setq cache (cdr cache))) | |
810 | (and res (null windows) (null cache)))) | |
811 | ||
e79016aa | 812 | (defun follow-windows-start-end (windows) |
782fbf2a | 813 | "Return a list of (WIN START END BUFFER-END-P) for window list WINDOWS." |
f3bfa025 KH |
814 | (if (follow-cache-valid-p windows) |
815 | follow-windows-start-end-cache | |
30bf4750 CY |
816 | (let ((orig-win (selected-window)) |
817 | win-start-end) | |
818 | (dolist (w windows) | |
819 | (select-window w) | |
820 | (push (cons w (cons (window-start) (follow-calc-win-end))) | |
821 | win-start-end)) | |
f3bfa025 | 822 | (select-window orig-win) |
30bf4750 | 823 | (setq follow-windows-start-end-cache (nreverse win-start-end))))) |
f3bfa025 | 824 | |
f3bfa025 | 825 | (defsubst follow-pos-visible (pos win win-start-end) |
e79016aa KH |
826 | "Non-nil when POS is visible in WIN." |
827 | (let ((wstart-wend-bend (cdr (assq win win-start-end)))) | |
828 | (and (>= pos (car wstart-wend-bend)) | |
30bf4750 | 829 | (or (< pos (cadr wstart-wend-bend)) |
e79016aa KH |
830 | (nth 2 wstart-wend-bend))))) |
831 | ||
832 | ||
30bf4750 | 833 | ;; By `aligned' we mean that for all adjacent windows, the end of the |
e79016aa KH |
834 | ;; first is equal with the start of the successor. The first window |
835 | ;; should start at a full screen line. | |
836 | ||
f3bfa025 | 837 | (defsubst follow-windows-aligned-p (win-start-end) |
782fbf2a CY |
838 | "Non-nil if the follower windows are aligned. |
839 | The argument, WIN-START-END, should be a list of the form | |
840 | returned by `follow-windows-start-end'." | |
841 | (let ((result t)) | |
842 | (while (and win-start-end result) | |
843 | (if (cdr win-start-end) | |
844 | (setq result (eq (nth 2 (car win-start-end)) | |
845 | (nth 1 (cadr win-start-end))))) | |
e79016aa | 846 | (setq win-start-end (cdr win-start-end))) |
782fbf2a | 847 | result)) |
e79016aa KH |
848 | |
849 | ;; Check if the point is visible in all windows. (So that | |
850 | ;; no one will be recentered.) | |
851 | ||
852 | (defun follow-point-visible-all-windows-p (win-start-end) | |
8cd3480b | 853 | "Non-nil when the `window-point' is visible in all windows." |
e79016aa KH |
854 | (let ((res t)) |
855 | (while (and res win-start-end) | |
f3bfa025 KH |
856 | (setq res (follow-pos-visible (window-point (car (car win-start-end))) |
857 | (car (car win-start-end)) | |
858 | win-start-end)) | |
e79016aa KH |
859 | (setq win-start-end (cdr win-start-end))) |
860 | res)) | |
861 | ||
862 | ||
5eba16a3 | 863 | ;; Make sure WIN always starts at the beginning of a whole screen |
e79016aa KH |
864 | ;; line. If WIN is not aligned the start is updated which probably |
865 | ;; will lead to a redisplay of the screen later on. | |
866 | ;; | |
867 | ;; This is used with the first window in a follow chain. The reason | |
868 | ;; is that we want to detect that the point is outside the window. | |
869 | ;; (Without the update, the start of the window will move as the | |
870 | ;; user presses BackSpace, and the other window redisplay routines | |
871 | ;; will move the start of the window in the wrong direction.) | |
872 | ||
873 | (defun follow-update-window-start (win) | |
874 | "Make sure that the start of WIN starts at a full screen line." | |
875 | (save-excursion | |
876 | (goto-char (window-start win)) | |
4484b97d | 877 | (unless (bolp) |
e79016aa | 878 | (vertical-motion 0 win) |
4484b97d | 879 | (unless (eq (point) (window-start win)) |
e79016aa KH |
880 | (vertical-motion 1 win) |
881 | (set-window-start win (point) 'noforce))))) | |
882 | ||
e79016aa KH |
883 | (defun follow-select-if-visible (dest win-start-end) |
884 | "Select and return a window, if DEST is visible in it. | |
885 | Return the selected window." | |
45fdb482 | 886 | (let (win wse) |
e79016aa | 887 | (while (and (not win) win-start-end) |
ff753438 | 888 | ;; Don't select a window that was just moved. This makes it |
782fbf2a CY |
889 | ;; possible to later select the last window after a |
890 | ;; `end-of-buffer' command. | |
891 | (setq wse (car win-start-end)) | |
892 | (when (follow-pos-visible dest (car wse) win-start-end) | |
45fdb482 | 893 | (setq win (car wse)) |
4484b97d | 894 | (select-window win)) |
e79016aa KH |
895 | (setq win-start-end (cdr win-start-end))) |
896 | win)) | |
897 | ||
5eba16a3 JB |
898 | ;; Lets select a window showing the end. Make sure we only select it if |
899 | ;; it wasn't just moved here. (I.e. M-> shall not unconditionally place | |
e79016aa KH |
900 | ;; the point in the selected window.) |
901 | ;; | |
da6062e6 | 902 | ;; (Compatibility kludge: in Emacs `window-end' is equal to `point-max'; |
e79016aa | 903 | ;; in XEmacs, it is equal to `point-max + 1'. Should I really bother |
cb02be17 | 904 | ;; checking `window-end' now when I check `end-of-buffer' explicitly?) |
e79016aa KH |
905 | |
906 | (defun follow-select-if-end-visible (win-start-end) | |
907 | "Select and return a window, if end is visible in it." | |
908 | (let ((win nil)) | |
909 | (while (and (not win) win-start-end) | |
ff753438 | 910 | ;; Don't select a window that was just moved. This makes it |
e79016aa KH |
911 | ;; possible to later select the last window after a `end-of-buffer' |
912 | ;; command. | |
913 | (if (and (eq (point-max) (nth 2 (car win-start-end))) | |
914 | (nth 3 (car win-start-end)) | |
ff753438 RS |
915 | ;; `window-end' might return nil. |
916 | (let ((end (window-end (car (car win-start-end))))) | |
917 | (and end | |
918 | (eq (point-max) (min (point-max) end))))) | |
e79016aa KH |
919 | (progn |
920 | (setq win (car (car win-start-end))) | |
921 | (select-window win))) | |
922 | (setq win-start-end (cdr win-start-end))) | |
923 | win)) | |
924 | ||
925 | ||
ff753438 | 926 | ;; Select a window that will display the point if the windows would |
e79016aa KH |
927 | ;; be redisplayed with the first window fixed. This is useful for |
928 | ;; example when the user has pressed return at the bottom of a window | |
929 | ;; as the point is not visible in any window. | |
930 | ||
931 | (defun follow-select-if-visible-from-first (dest windows) | |
30bf4750 CY |
932 | "Try to select one of WINDOWS without repositioning the topmost window. |
933 | If one of the windows in WINDOWS contains DEST, select it, call | |
934 | `follow-redisplay', move point to DEST, and return that window. | |
935 | Otherwise, return nil." | |
936 | (let (win end-pos-end-p) | |
e79016aa KH |
937 | (save-excursion |
938 | (goto-char (window-start (car windows))) | |
939 | ;; Make sure the line start in the beginning of a real screen | |
940 | ;; line. | |
cb02be17 | 941 | (vertical-motion 0 (car windows)) |
30bf4750 | 942 | (when (>= dest (point)) |
e79016aa KH |
943 | ;; At or below the start. Check the windows. |
944 | (save-window-excursion | |
30bf4750 CY |
945 | (let ((windows windows)) |
946 | (while (and (not win) windows) | |
947 | (set-window-start (car windows) (point) 'noforce) | |
948 | (setq end-pos-end-p (follow-calc-win-end (car windows))) | |
949 | (goto-char (car end-pos-end-p)) | |
c93b886f CY |
950 | ;; Visible, if dest above end, or if eob is visible |
951 | ;; inside the window. | |
30bf4750 CY |
952 | (if (or (car (cdr end-pos-end-p)) |
953 | (< dest (point))) | |
e79016aa | 954 | (setq win (car windows)) |
30bf4750 CY |
955 | (setq windows (cdr windows)))))))) |
956 | (when win | |
957 | (select-window win) | |
958 | (follow-redisplay windows (car windows)) | |
959 | (goto-char dest)) | |
e79016aa KH |
960 | win)) |
961 | ||
c93b886f | 962 | ;;; Redisplay |
e79016aa KH |
963 | |
964 | ;; Redraw all the windows on the screen, starting with the top window. | |
c80e3b4a | 965 | ;; The window used as as marker is WIN, or the selected window if WIN |
4484b97d CY |
966 | ;; is nil. Start every window directly after the end of the previous |
967 | ;; window, to make sure long lines are displayed correctly. | |
e79016aa | 968 | |
30bf4750 | 969 | (defun follow-redisplay (&optional windows win preserve-win) |
e79016aa KH |
970 | "Reposition the WINDOWS around WIN. |
971 | Should the point be too close to the roof we redisplay everything | |
8cd3480b | 972 | from the top. WINDOWS should contain a list of windows to |
5eba16a3 | 973 | redisplay; it is assumed that WIN is a member of the list. |
e79016aa KH |
974 | Should WINDOWS be nil, the windows displaying the |
975 | same buffer as WIN, in the current frame, are used. | |
30bf4750 CY |
976 | Should WIN be nil, the selected window is used. |
977 | If PRESERVE-WIN is non-nil, keep WIN itself unchanged while | |
978 | repositioning the other windows." | |
4484b97d CY |
979 | (or win (setq win (selected-window))) |
980 | (or windows (setq windows (follow-all-followers win))) | |
981 | ;; Calculate the start of the first window. | |
982 | (let* ((old-win-start (window-start win)) | |
983 | (try-first-start (follow-estimate-first-window-start | |
984 | windows win old-win-start)) | |
985 | (try-win-start (follow-calc-win-start | |
986 | windows try-first-start win)) | |
987 | (start (cond ((= try-win-start old-win-start) | |
988 | (follow-debug-message "exact") | |
989 | try-first-start) | |
990 | ((< try-win-start old-win-start) | |
991 | (follow-debug-message "above") | |
992 | (follow-calculate-first-window-start-from-above | |
993 | windows try-first-start win old-win-start)) | |
994 | (t | |
995 | (follow-debug-message "below") | |
996 | (follow-calculate-first-window-start-from-below | |
997 | windows try-first-start win old-win-start))))) | |
998 | (dolist (w windows) | |
30bf4750 CY |
999 | (unless (and preserve-win (eq w win)) |
1000 | (set-window-start w start)) | |
4484b97d | 1001 | (setq start (car (follow-calc-win-end w)))))) |
e79016aa | 1002 | |
e79016aa KH |
1003 | (defun follow-estimate-first-window-start (windows win start) |
1004 | "Estimate the position of the first window. | |
4484b97d CY |
1005 | The estimate is computed by assuming that the window WIN, which |
1006 | should be a member of WINDOWS, starts at position START." | |
1007 | (let ((windows-before (car (follow-split-followers windows win)))) | |
e79016aa KH |
1008 | (save-excursion |
1009 | (goto-char start) | |
e79016aa | 1010 | (vertical-motion 0 win) |
4484b97d CY |
1011 | (dolist (w windows-before) |
1012 | (vertical-motion (- 1 (window-text-height w)) w)) | |
1013 | (point)))) | |
e79016aa KH |
1014 | |
1015 | ||
1016 | ;; Find the starting point, start at GUESS and search downward. | |
1017 | ;; The returned point is always a point below GUESS. | |
1018 | ||
cb02be17 | 1019 | (defun follow-calculate-first-window-start-from-above |
e79016aa KH |
1020 | (windows guess win start) |
1021 | (save-excursion | |
1022 | (let ((done nil) | |
1023 | win-start | |
1024 | res) | |
1025 | (goto-char guess) | |
1026 | (while (not done) | |
1027 | (if (not (= (vertical-motion 1 (car windows)) 1)) | |
1028 | ;; Hit bottom! (Can we really do this?) | |
1029 | ;; We'll keep it, since it ensures termination. | |
1030 | (progn | |
1031 | (setq done t) | |
1032 | (setq res (point-max))) | |
1033 | (setq win-start (follow-calc-win-start windows (point) win)) | |
1034 | (if (>= win-start start) | |
4484b97d | 1035 | (setq done t res (point))))) |
e79016aa KH |
1036 | res))) |
1037 | ||
1038 | ||
1039 | ;; Find the starting point, start at GUESS and search upward. Return | |
1040 | ;; a point on the same line as GUESS, or above. | |
e79016aa KH |
1041 | |
1042 | (defun follow-calculate-first-window-start-from-below | |
1043 | (windows guess &optional win start) | |
1044 | (setq win (or win (selected-window))) | |
1045 | (setq start (or start (window-start win))) | |
1046 | (save-excursion | |
13d5c73f | 1047 | (let (done win-start res opoint) |
fc779383 | 1048 | ;; Always calculate what happens when no line is displayed in the first |
e79016aa KH |
1049 | ;; window. (The `previous' res is needed below!) |
1050 | (goto-char guess) | |
1051 | (vertical-motion 0 (car windows)) | |
1052 | (setq res (point)) | |
1053 | (while (not done) | |
13d5c73f | 1054 | (setq opoint (point)) |
e79016aa KH |
1055 | (if (not (= (vertical-motion -1 (car windows)) -1)) |
1056 | ;; Hit roof! | |
4484b97d | 1057 | (setq done t res (point-min)) |
e79016aa | 1058 | (setq win-start (follow-calc-win-start windows (point) win)) |
13d5c73f CY |
1059 | (cond ((>= (point) opoint) |
1060 | ;; In some pathological cases, vertical-motion may | |
1061 | ;; return -1 even though point has not decreased. In | |
1062 | ;; that case, avoid looping forever. | |
1063 | (setq done t res (point))) | |
1064 | ((= win-start start) ; Perfect match, use this value | |
1065 | (setq done t res (point))) | |
5eba16a3 | 1066 | ((< win-start start) ; Walked to far, use previous result |
e79016aa KH |
1067 | (setq done t)) |
1068 | (t ; Store result for next iteration | |
1069 | (setq res (point)))))) | |
1070 | res))) | |
1071 | ||
c93b886f | 1072 | ;;; Avoid tail recenter |
e79016aa | 1073 | |
782fbf2a CY |
1074 | ;; This sets the window internal flag `force_start'. The effect is |
1075 | ;; that windows only displaying the tail aren't recentered. | |
e79016aa | 1076 | ;; |
782fbf2a CY |
1077 | ;; A window displaying only the tail, is a window whose window-start |
1078 | ;; position is equal to (point-max) of the buffer it displays. | |
e79016aa | 1079 | |
06b60517 | 1080 | (defun follow-avoid-tail-recenter (&rest _rest) |
e79016aa | 1081 | "Make sure windows displaying the end of a buffer aren't recentered. |
7194219d | 1082 | This is done by reading and rewriting the start position of |
17f6d002 | 1083 | non-first windows in Follow mode." |
782fbf2a | 1084 | (let* ((orig-buffer (current-buffer)) |
12b4c0ea | 1085 | (top (frame-first-window)) |
782fbf2a CY |
1086 | (win top) |
1087 | who) ; list of (buffer . frame) | |
1088 | ;; If the only window in the frame is a minibuffer | |
1089 | ;; window, `next-window' will never find it again... | |
1090 | (unless (window-minibuffer-p top) | |
1091 | (while ;; look, no body! | |
1092 | (let ((start (window-start win)) | |
1093 | (pair (cons (window-buffer win) (window-frame win)))) | |
1094 | (set-buffer (window-buffer win)) | |
1095 | (cond ((null (member pair who)) | |
1096 | (setq who (cons pair who))) | |
1097 | ((and follow-mode (eq (point-max) start)) | |
1098 | ;; Write the same window start back, but don't | |
1099 | ;; set the NOFORCE flag. | |
1100 | (set-window-start win start))) | |
1101 | (setq win (next-window win 'not t)) | |
1102 | (not (eq win top)))) ;; Loop while this is true. | |
1103 | (set-buffer orig-buffer)))) | |
e79016aa | 1104 | |
c93b886f | 1105 | ;;; Post Command Hook |
e79016aa | 1106 | |
08a1dbe6 | 1107 | ;; The magic little box. This function is called after every command. |
e79016aa KH |
1108 | |
1109 | ;; This is not as complicated as it seems. It is simply a list of common | |
1110 | ;; display situations and the actions to take, plus commands for redrawing | |
1111 | ;; the screen if it should be unaligned. | |
1112 | ;; | |
1113 | ;; We divide the check into two parts; whether we are at the end or not. | |
99dfcc0d | 1114 | ;; This is due to the fact that the end can actually be visible |
e79016aa KH |
1115 | ;; in several window even though they are aligned. |
1116 | ||
1117 | (defun follow-post-command-hook () | |
cb02be17 | 1118 | "Ensure that the windows in Follow mode are adjacent after each command." |
4484b97d CY |
1119 | (unless (input-pending-p) |
1120 | (let ((follow-inside-post-command-hook t) | |
1121 | (win (selected-window))) | |
e79016aa | 1122 | ;; Work in the selected window, not in the current buffer. |
4484b97d CY |
1123 | (with-current-buffer (window-buffer win) |
1124 | (unless (and (symbolp this-command) | |
1125 | (get this-command 'follow-mode-use-cache)) | |
782fbf2a CY |
1126 | (setq follow-windows-start-end-cache nil))) |
1127 | (follow-adjust-window win (point))))) | |
1128 | ||
1129 | (defun follow-adjust-window (win dest) | |
1130 | ;; Adjust the window WIN and its followers. | |
1131 | (with-current-buffer (window-buffer win) | |
1132 | (when (and follow-mode | |
1133 | (not (window-minibuffer-p win))) | |
1134 | (let* ((windows (follow-all-followers win)) | |
1135 | (win-start-end (progn | |
1136 | (follow-update-window-start (car windows)) | |
1137 | (follow-windows-start-end windows))) | |
1138 | (aligned (follow-windows-aligned-p win-start-end)) | |
1139 | (visible (follow-pos-visible dest win win-start-end)) | |
1140 | selected-window-up-to-date) | |
1141 | (unless (and aligned visible) | |
1142 | (setq follow-windows-start-end-cache nil)) | |
1143 | ||
1144 | ;; Select a window to display point. | |
1145 | (unless follow-internal-force-redisplay | |
1146 | (if (eq dest (point-max)) | |
1147 | ;; Be careful at point-max: the display can be aligned | |
1148 | ;; while DEST can be visible in several windows. | |
1149 | (cond | |
1150 | ;; Select the current window, but only when the display | |
1151 | ;; is correct. (When inserting characters in a tail | |
1152 | ;; window, the display is not correct, as they are | |
1153 | ;; shown twice.) | |
1154 | ;; | |
1155 | ;; Never stick to the current window after a deletion. | |
1156 | ;; Otherwise, when typing `DEL' in a window showing | |
1157 | ;; only the end of the file, a character would be | |
1158 | ;; removed from the window above, which is very | |
1159 | ;; unintuitive. | |
1160 | ((and visible | |
1161 | aligned | |
1162 | (not (memq this-command | |
1163 | '(backward-delete-char | |
1164 | delete-backward-char | |
1165 | backward-delete-char-untabify | |
1166 | kill-region)))) | |
1167 | (follow-debug-message "Max: same")) | |
1168 | ;; If the end is visible, and the window doesn't | |
1169 | ;; seems like it just has been moved, select it. | |
1170 | ((follow-select-if-end-visible win-start-end) | |
1171 | (follow-debug-message "Max: end visible") | |
1172 | (setq visible t aligned nil) | |
1173 | (goto-char dest)) | |
1174 | ;; Just show the end... | |
1175 | (t | |
1176 | (follow-debug-message "Max: default") | |
1177 | (select-window (car (last windows))) | |
1178 | (goto-char dest) | |
1179 | (setq visible nil aligned nil))) | |
1180 | ||
1181 | ;; We're not at the end, here life is much simpler. | |
1182 | (cond | |
1183 | ;; This is the normal case! | |
1184 | ;; It should be optimized for speed. | |
1185 | ((and visible aligned) | |
1186 | (follow-debug-message "same")) | |
1187 | ;; Pick a position in any window. If the display is ok, | |
1188 | ;; this picks the `correct' window. | |
1189 | ((follow-select-if-visible dest win-start-end) | |
1190 | (follow-debug-message "visible") | |
1191 | (goto-char dest) | |
1192 | ;; Perform redisplay, in case line is partially visible. | |
1193 | (setq visible nil)) | |
1194 | ;; Not visible anywhere else, lets pick this one. | |
1195 | (visible | |
1196 | (follow-debug-message "visible in selected.")) | |
1197 | ;; If DEST is before the first window start, select the | |
1198 | ;; first window. | |
1199 | ((< dest (nth 1 (car win-start-end))) | |
1200 | (follow-debug-message "before first") | |
1201 | (select-window (car windows)) | |
1202 | (goto-char dest) | |
1203 | (setq visible nil aligned nil)) | |
1204 | ;; If we can position the cursor without moving the first | |
1205 | ;; window, do it. This is the case that catches `RET' at | |
1206 | ;; the bottom of a window. | |
1207 | ((follow-select-if-visible-from-first dest windows) | |
1208 | (follow-debug-message "Below first") | |
1209 | (setq visible t aligned t)) | |
1210 | ;; None of the above. Stick to the selected window. | |
1211 | (t | |
1212 | (follow-debug-message "None") | |
1213 | (setq visible nil aligned nil)))) | |
1214 | ||
1215 | ;; If a new window was selected, make sure that the old is | |
1216 | ;; not scrolled when the point is outside the window. | |
1217 | (unless (eq win (selected-window)) | |
1218 | (let ((p (window-point win))) | |
1219 | (set-window-start win (window-start win) nil) | |
1220 | (set-window-point win p)))) | |
1221 | ||
1222 | (unless visible | |
1223 | ;; If point may not be visible in the selected window, | |
1224 | ;; perform a redisplay; this ensures scrolling. | |
1225 | (let ((opoint (point))) | |
1226 | (redisplay) | |
1227 | ;; If this `redisplay' moved point, we got clobbered by a | |
1228 | ;; previous call to `set-window-start'. Try again. | |
1229 | (when (/= (point) opoint) | |
1230 | (goto-char opoint) | |
1231 | (redisplay))) | |
1232 | ||
1233 | (setq selected-window-up-to-date t) | |
1234 | (follow-avoid-tail-recenter) | |
1235 | (setq win-start-end (follow-windows-start-end windows) | |
1236 | follow-windows-start-end-cache nil | |
1237 | aligned nil)) | |
1238 | ||
1239 | ;; Now redraw the windows around the selected window. | |
1240 | (unless (and (not follow-internal-force-redisplay) | |
1241 | (or aligned | |
1242 | (follow-windows-aligned-p win-start-end)) | |
1243 | (follow-point-visible-all-windows-p win-start-end)) | |
1244 | (setq follow-internal-force-redisplay nil) | |
1245 | (follow-redisplay windows (selected-window) | |
1246 | selected-window-up-to-date) | |
1247 | (setq win-start-end (follow-windows-start-end windows) | |
1248 | follow-windows-start-end-cache nil) | |
1249 | ;; The point can ends up in another window when DEST is at | |
1250 | ;; the beginning of the buffer and the selected window is | |
1251 | ;; not the first. It can also happen when long lines are | |
1252 | ;; used and there is a big difference between the width of | |
1253 | ;; the windows. (When scrolling one line in a wide window | |
1254 | ;; which will cause a move larger that an entire small | |
1255 | ;; window.) | |
1256 | (unless (follow-pos-visible dest win win-start-end) | |
1257 | (follow-select-if-visible dest win-start-end) | |
1258 | (goto-char dest))) | |
1259 | ||
1260 | ;; If the region is visible, make it look good when spanning | |
1261 | ;; multiple windows. | |
1262 | (when (region-active-p) | |
1263 | (follow-maximize-region | |
1264 | (selected-window) windows win-start-end))) | |
1265 | ||
1266 | ;; Whether or not the buffer was in follow mode, update windows | |
1267 | ;; displaying the tail so that Emacs won't recenter them. | |
1268 | (follow-avoid-tail-recenter)))) | |
e79016aa | 1269 | |
c93b886f | 1270 | ;;; The region |
e79016aa KH |
1271 | |
1272 | ;; Tries to make the highlighted area representing the region look | |
cb02be17 | 1273 | ;; good when spanning several windows. |
e79016aa KH |
1274 | ;; |
1275 | ;; Not perfect, as the point can't be placed at window end, only at | |
cb02be17 | 1276 | ;; end-1. This will highlight a little bit in windows above |
e79016aa KH |
1277 | ;; the current. |
1278 | ||
1279 | (defun follow-maximize-region (win windows win-start-end) | |
cb02be17 | 1280 | "Make a highlighted region stretching multiple windows look good." |
e79016aa KH |
1281 | (let* ((all (follow-split-followers windows win)) |
1282 | (pred (car all)) | |
1283 | (succ (cdr all)) | |
1284 | data) | |
1285 | (while pred | |
1286 | (setq data (assq (car pred) win-start-end)) | |
1287 | (set-window-point (car pred) (max (nth 1 data) (- (nth 2 data) 1))) | |
1288 | (setq pred (cdr pred))) | |
1289 | (while succ | |
1290 | (set-window-point (car succ) (nth 1 (assq (car succ) win-start-end))) | |
1291 | (setq succ (cdr succ))))) | |
1292 | ||
c93b886f | 1293 | ;;; Scroll bar |
e79016aa KH |
1294 | |
1295 | ;;;; Scroll-bar support code. | |
1296 | ||
782fbf2a CY |
1297 | ;; This handles the case where the user drags the scroll bar of a |
1298 | ;; non-selected window whose buffer is in Follow mode. | |
1299 | ||
1300 | (defun follow-scroll-bar-toolkit-scroll (event) | |
1301 | (interactive "e") | |
1302 | (scroll-bar-toolkit-scroll event) | |
1303 | (follow-redraw-after-event event)) | |
1304 | ||
1305 | (defun follow-scroll-bar-drag (event) | |
1306 | (interactive "e") | |
1307 | (scroll-bar-drag event) | |
1308 | (follow-redraw-after-event event)) | |
1309 | ||
1310 | (defun follow-scroll-bar-scroll-up (event) | |
1311 | (interactive "e") | |
1312 | (scroll-bar-scroll-up event) | |
1313 | (follow-redraw-after-event event)) | |
1314 | ||
1315 | (defun follow-scroll-bar-scroll-down (event) | |
1316 | (interactive "e") | |
1317 | (scroll-bar-scroll-down event) | |
1318 | (follow-redraw-after-event event)) | |
1319 | ||
87233a14 CY |
1320 | (defun follow-mwheel-scroll (event) |
1321 | (interactive "e") | |
1322 | (mwheel-scroll event) | |
1323 | (follow-redraw-after-event event)) | |
1324 | ||
782fbf2a | 1325 | (defun follow-redraw-after-event (event) |
87233a14 CY |
1326 | "Re-align the Follow mode windows affected by EVENT." |
1327 | (let* ((window (nth 0 (event-end event))) | |
1328 | (buffer (window-buffer window)) | |
1329 | (orig-win (selected-window))) | |
1330 | (when (and (buffer-local-value 'follow-mode buffer) | |
782fbf2a CY |
1331 | ;; Ignore the case where we scroll the selected window; |
1332 | ;; that is handled by the post-command hook function. | |
1333 | (not (eq window (selected-window)))) | |
1334 | (select-window window) | |
1335 | (follow-redisplay) | |
87233a14 CY |
1336 | (unless (eq (window-buffer orig-win) buffer) |
1337 | (select-window orig-win))))) | |
e79016aa | 1338 | |
c93b886f | 1339 | ;;; Window size change |
e79016aa | 1340 | |
782fbf2a CY |
1341 | ;; The functions in `window-size-change-functions' are called every |
1342 | ;; time a window in a frame changes size, most notably after the frame | |
1343 | ;; has been resized. We call `follow-post-command-hook' for every | |
1344 | ;; Follow mode buffer visible in any window in the resized frame. | |
e79016aa | 1345 | ;; |
782fbf2a CY |
1346 | ;; Since `follow-window-size-change' can be called indirectly from |
1347 | ;; `follow-post-command-hook' we have a potential infinite loop. To | |
1348 | ;; avoid this, we simply do not do anything in this situation. The | |
1349 | ;; variable `follow-inside-post-command-hook' contains information | |
1350 | ;; about whether the execution actually is inside the | |
e79016aa KH |
1351 | ;; post-command-hook or not. |
1352 | ||
e79016aa KH |
1353 | (defun follow-window-size-change (frame) |
1354 | "Redraw all windows in FRAME, when in Follow mode." | |
782fbf2a CY |
1355 | ;; Below, we call `post-command-hook'. Avoid an infloop. |
1356 | (unless follow-inside-post-command-hook | |
e79016aa KH |
1357 | (let ((buffers '()) |
1358 | (orig-window (selected-window)) | |
1359 | (orig-buffer (current-buffer)) | |
1360 | (orig-frame (selected-frame)) | |
1361 | windows | |
1362 | buf) | |
1363 | (select-frame frame) | |
1364 | (unwind-protect | |
cb02be17 | 1365 | (walk-windows |
782fbf2a CY |
1366 | (lambda (win) |
1367 | (setq buf (window-buffer win)) | |
1368 | (unless (memq buf buffers) | |
1369 | (set-buffer buf) | |
1370 | (when follow-mode | |
1371 | (setq windows (follow-all-followers win)) | |
1372 | (if (not (memq orig-window windows)) | |
1373 | (follow-redisplay windows win) | |
1374 | ;; Make sure we're redrawing around the selected | |
1375 | ;; window. | |
1376 | (select-window orig-window) | |
1377 | (follow-post-command-hook) | |
1378 | (setq orig-window (selected-window))) | |
1379 | (setq buffers (cons buf buffers))))) | |
1380 | 'no-minibuf) | |
e79016aa KH |
1381 | (select-frame orig-frame) |
1382 | (set-buffer orig-buffer) | |
1383 | (select-window orig-window))))) | |
1384 | ||
782fbf2a | 1385 | (add-hook 'window-scroll-functions 'follow-avoid-tail-recenter t) |
e79016aa | 1386 | |
c93b886f | 1387 | ;;; Profile support |
e79016aa KH |
1388 | |
1389 | ;; The following (non-evaluated) section can be used to | |
1390 | ;; profile this package using `elp'. | |
1391 | ;; | |
1392 | ;; Invalid indentation on purpose! | |
1393 | ||
782fbf2a CY |
1394 | ;; (setq elp-function-list |
1395 | ;; '(window-end | |
1396 | ;; vertical-motion | |
1397 | ;; follow-mode | |
1398 | ;; follow-all-followers | |
1399 | ;; follow-split-followers | |
1400 | ;; follow-redisplay | |
1401 | ;; follow-estimate-first-window-start | |
1402 | ;; follow-calculate-first-window-start-from-above | |
1403 | ;; follow-calculate-first-window-start-from-below | |
1404 | ;; follow-calc-win-end | |
1405 | ;; follow-calc-win-start | |
1406 | ;; follow-pos-visible | |
1407 | ;; follow-windows-start-end | |
1408 | ;; follow-cache-valid-p | |
1409 | ;; follow-select-if-visible | |
1410 | ;; follow-select-if-visible-from-first | |
1411 | ;; follow-windows-aligned-p | |
1412 | ;; follow-point-visible-all-windows-p | |
1413 | ;; follow-avoid-tail-recenter | |
1414 | ;; follow-update-window-start | |
1415 | ;; follow-post-command-hook)) | |
fc779383 | 1416 | |
e79016aa KH |
1417 | (provide 'follow) |
1418 | ||
e79016aa KH |
1419 | ;; /------------------------------------------------------------------------\ |
1420 | ;; | "I [..] am rarely happier then when spending an entire day programming | | |
1421 | ;; | my computer to perform automatically a task that it would otherwise | | |
1422 | ;; | take me a good ten seconds to do by hand. Ten seconds, I tell myself, | | |
1423 | ;; | is ten seconds. Time is valuable and ten seconds' worth of it is well | | |
1424 | ;; | worth the investment of a day's happy activity working out a way to | | |
1425 | ;; | save it". -- Douglas Adams, "Last Chance to See" | | |
1426 | ;; \------------------------------------------------------------------------/ | |
1427 | ||
1428 | ;;; follow.el ends here |